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Information × Registration Number 0219U003047, 0116U002519 , R & D reports Title Regioselective synthesis of epoxy compounds with different topologies popup.stage_title Head Shved Elena N., Доктор хімічних наук Registration Date 16-01-2019 Organization Donetsk State University popup.description2 The structure effect of carboxylic acids on the nucleophilic oxirane ring opening in the presence of organic bases - tertiary amines and tetraalkylammonium salts - has been established by kinetic, spectral, quantum chemical, and correlation methods. The kinetic characteristics and activation parameters of the reaction in the system "epichlorohydrin - protonodor - base" have been determined. The structure effect of the acid on the rate of the oxirane ring opening has been investigated. To study the electronic and steric effect of the acidic reagent structure, the ring opening of epichlorohydrin by the series of carboxylate anions has been carried out; equilibrium configurations of reactants, transition states and products of the reaction of epichlorohydrin with carboxylate anions of various structure have been found. According to the More O'Ferrall - Jencks diagram, it has been shown that the transition states of the reaction pathway have dissociative nature. It has been determined that the increase in steric hindrances (TSEI) in the carboxyl group decreases the rate of oxirane acidolysis. A cross-correlation analysis of the kinetic and activation characteristics has been carried out for the reactions of symmetrical trans-2,3-diaryloxirane with arene-sulfonic acids in a mixture of dioxane and 1,2-dichloroethane. Confirmation of the phenomenon of isoparametricity in the enthalpy-entropy compensation aspect has been obtained. The isoparametric point has been experimentally reached at 265 K. The properties of amine- and anhydride- cured epoxy-polysiloxane composites with a SiO2 content of 0.5-6 wt. % and 1-3 wt. % respectively have been investigated. It has been established that the synthesized composites are characterized by high chemical resistance. The maximum factor of impact strength have been demonstrated by anhydride-cured systems with a PSP (polysiloxane particles) content of 1 wt. %. It has been determined that the protective properties of amine-cured composites do not depend on the content of PSP in the range of 0.5-6 wt. %, the effectiveness of the anticorrosive protection of the alloy D16 with these coatings is more than 90%. In the case of anhydride-cured systems, the best electrochemical properties have been shown by the composite material with a PSP content of 1 wt. %, obtained within the PSP sol formation without adding the epoxy oligomer. Product Description popup.authors Бахалова Є.А. Беспалько Юлія Миколаївна Жильцова Світлана Віталіївна Калінський Олександр Михайлович Леонова Наталя Геннадіївна Ситник Наталія Сергіївна Швед Олена Миколаївна Шпанько Ігор Вальович Ютілова Ксенія Сергіївна popup.nrat_date 2020-04-02 Close